Method of controlling dishwasher

ABSTRACT

A dishwasher and a method of controlling a dishwasher are provided. The method includes heating wash fluid in a washing tub when no dishes are loaded in the washing tub, and sterilizing the washing tub by spraying the heated wash fluid into the washing tub with the use of a wash fluid spray device. Therefore, it is possible to remove wash fluid and impurities remaining in the washing tub and to prevent an offensive odor from being emitted from the washing tub.

This application claims priority to Korean Patent Application No. 10-2007-0096734 filed in Korea on Sep. 21, 2007, the disclosure of which is incorporated herein by reference in its entirety.

BACKGROUND

1. Field

A dishwasher and a method of controlling a dishwasher are provided, and more particularly, a dishwasher and a method of controlling a dishwasher are provided in which a washing tub can be effectively sterilized and washed.

2. Background

Dishwashers are devices for washing dishes soiled with food residues by spraying wash fluid onto the dishes. Dishwashers include a washing tub having racks for holding dishes, a fluid supply device supplying clean wash fluid to a sump disposed below the washing tub, a wash fluid spray device spraying the wash fluid supplied from the sump toward the racks so as to clean the dishes, and a drain device discharging waste wash fluid resulting from the washing of the dishes.

Wash fluid and impurities may remain in a washing tub even after a dishwashing operation is complete. Thus, the washing tub may emit an offensive odor due to the eventual decomposition of wash fluid and impurities in the washing tub. In order to address this, the washing tub should be washed often. However, it is generally difficult to clean the washing tub, and even more difficult to clean the wash fluid spray device and the sump.

SUMMARY

A dishwasher and a method of controlling a dishwasher are provided in which an offensive odor can be prevented from being emitted from a washing tub after a long use of the washing tub by sterilizing and washing the washing tub.

A method of controlling a dishwasher as embodied and broadly described herein may include heating wash water in a washing tub when no dishes are loaded in the washing tub; and sterilizing the washing tub by spraying the heated wash water into the washing tub with the use of a wash water spray device.

A dishwasher as embodied and broadly described herein may include a washing tub in which dishes are loaded and washed; a wash water spray device which washes the dishes by spraying wash water into the washing tub; a heating device which heats the wash water; and a control unit which controls the heating device to heat the wash water and controls the wash water spray device to spray the heated wash water into the washing tub and thus to sterilize and wash the washing tub when no dishes are loaded in the washing tub.

In a dishwasher and a method as embodied and broadly described herein, it is possible to effectively remove wash water and impurities remaining in a washing tub so as to prevent an offensive odor from being emitted from the washing tub by washing the washing tub with high-temperature wash water when no dishes are loaded in the washing tub.

Therefore, it is possible to improve the performance of a dishwasher and maximize user convenience.

BRIEF DESCRIPTION OF THE DRAWINGS

The embodiments will be described in detail with reference to the following drawings in which like reference numerals refer to like elements wherein:

FIG. 1 is a perspective view of a dishwasher according to an embodiment as broadly described herein;

FIG. 2 is a cross-sectional view of the dishwasher shown in FIG. 1;

FIG. 3 is a block diagram of the dishwasher shown in FIG. 1;

FIG. 4 is a flowchart of a method of controlling a dishwasher according to an embodiment as broadly described herein; and

FIG. 5 is a block diagram of a dishwasher according to another embodiment as broadly described herein.

DETAILED DESCRIPTION

Referring to FIGS. 1 and 2, a dishwasher 1 includes a cabinet 2, which forms the exterior of the dishwasher 1, a washing tub 4, which is disposed in the cabinet 2 and has a space for washing dishes loaded therein, a plurality of rack assemblies 6 and 8, which are movably disposed in the washing tub 4, and a wash fluid spray device 10, which is disposed in the washing tub 4 and sprays wash fluid onto dishes held by the rack assemblies 6 and 8.

Each of the cabinet 2 and the washing tub 4 has an opening at the front, and thus, dishes can be loaded onto the rack assemblies 6 and 8 in the tub 4 through the openings of the cabinet 2 and the washing tub 4. A door 12 is disposed so as to be able to open or close the cabinet 2, for example, in a drop-down manner. A detergent supply device 14 is disposed on a rear surface of the door 12 to supply detergent or rinsing agent into the washing tub 4. A manipulation device 16 is disposed at an upper part of the front of the door 12 to allow a user to control the operation of the dishwasher 1. The manipulation device 16 includes a plurality of switches 16 a and 16 b. The user may choose and set a dishwashing program by manipulating one of the switches 16 a and 16 b.

Referring to FIGS. 1 through 3, a sump 18 is disposed below the washing tub 4. The sump 18 contains wash fluid. A heating device 20 is disposed in the sump 18 and heats the wash fluid contained in the sump 18. A sheath heater having excellent watertight properties may be used as the heating device 20. A temperature detector 22 is disposed in the sump 18. The temperature detector 22 measures the fluid temperature in the sump 18. The temperature detector 22 may include a thermistor which is disposed in the sump 18 so as to be able to contact fluid water in the sump 18.

A fluid supply device 24 is connected to a first side of the sump 18. The supply device 24 supplies clean wash fluid provided by an external source into the sump 18. A drain device 26 is connected to a second side of the sump 18. The drain device 26 discharges wash fluid used to clean dishes from the dishwasher 1. The supply device 24 includes a fluid supply path (not shown) connecting the first side of the sump 18 to the external source and a fluid supply valve (not shown) disposed on the fluid supply path. The supply of wash fluid into the sump 18 may be controlled by opening or closing the supply valve. The drain device 26 includes a drain path (not shown) disposed between the second side of the sump 18 and the outside of the dishwasher 1 and a drain pump (not shown) disposed on the drain path. The wash fluid contained in the sump 18 may be pumped out of the dishwasher 1 by the drain pump.

Referring to FIGS. 1 and 2, the rack assemblies 6 and 8 include a first rack assembly 6 disposed in a lower part of the washing tub 4 so as to be able to be withdrawn from the washing tub 4 and a second rack assembly 8 disposed in an upper part of the washing tub 4 so as to be able to be withdrawn from the washing tub 6. The first rack assembly 6 includes a first rack 6 a and a plurality of wheels 6 b. The first rack 6 a is disposed in the washing tub 4 such that both lateral sides of the first rack assembly 6 can slide along corresponding inner surfaces of the washing tub 4. The first rack 6 a may hold dishes therein. The wheels 6 b are disposed under the first rack 6 a and roll along the bottom surface of the washing tub 4 and the rear surface or the door 12. The second rack assembly 8 includes a second rack 8 a and guide rails 8 b. The second rack 8 a is disposed above the first rack 6 a and may hold dishes therein. The guide rails 8 b are disposed on both sides of the second rack 8 a and support the second rack 8 a so that the second rack 8 a can move back and forth.

Referring to FIGS. 1 and 2, the wash fluid spray device 10 includes a washing pump 30, which is connected to the sump 18 and pumps wash fluid into the sump 18, a plurality of nozzle devices 32 and 34, which spray the wash fluid pumped by the washing pump 30 onto the dishes held by the first and second rack assemblies 6 and 8, and a wash fluid flow path 36, which is formed between the washing pump 30 and the nozzle devices 32 and 34. The nozzle devices 32 and 34 include a first nozzle device 32, which is rotatably disposed below the first rack 6 a and sprays wash fluid onto the dishes held by the first rack 6 a, and a second nozzle device 34, which is rotatably disposed below the second rack 8 a and sprays wash fluid onto the dishes held by the second rack 8 a.

Referring to FIGS. 2 and 3, a controller 38 is disposed at the door 12 or the cabinet 2 to control operation of the dishwasher 1. The controller 38 includes a timer 40, which measures the operating time of the dishwasher 1. In the exemplary embodiment of FIGS. 1 through 3, the controller 38 may be disposed in an upper part of the door 12. A drying device 42 is disposed between the cabinet 2 and the washing tub 4 and supplies dry air into the washing tub 4. The drying device 42 includes a blower, which blows external air into the washing tub 4 and discharges air from the washing tub 4, and a heater, which heats air injected into the washing tub 4 by the blower.

A method of controlling the dishwasher 1 according to an exemplary embodiment will hereinafter be described in detail.

The door 12 is pulled down so as to open the washing tub 4, and the first and second racks 6 a and 8 a of the first and second rack assemblies 6 and 8 are withdrawn from the washing tub 4. Thereafter, dishes are placed on each of the first and second racks 6 a and 8 a, and the first and second racks 6 a and 8 b are put back in the washing tub 4. Thereafter, the door 12 is closed so as to close the washing tub 4.

Thereafter, a washing program is chosen for the dishwasher 1 by manipulating the manipulation device 16 at the door 12, and the dishwasher 1 is driven. The chosen washing program is input to the controller 38, and the controller 38 controls the operation of the dishwasher 1 according to the chosen washing program.

That is, the controller 38 drives the fluid supply device 24 and thus supplies clean wash fluid into the sump 18. If wash fluid is supplied into the sump 18 to a predefined level, the controller 38 washes the dishes by driving the heating device 20 and the wash fluid spray device 10. More specifically, the wash fluid contained in the sump 18 is sprayed onto the dishes by the spray device 10. The heating device 20 heats the wash fluid in the sump 18, thereby improving the dishwashing performance of the spray device 10. The heating device 20 may heat the wash fluid in the sump 18 to a temperature of about 45° C. during the washing of the dishes. During the washing of the dishes, the controller 38 supplies detergent into the washing tub 4 by driving the detergent supply device 14.

Once the washing of the dishes is complete, the controller 38 compares the time taken to wash the dishes with a first set time. If the time taken to wash the dishes does not exceed the first set time, the controller 38 terminates the operations of the heating device 20 and the spray device 10, and drains the sump 18 by driving the drain device 26. Thereafter, the controller 38 drives the fluid supply device 24 and thus supplies clean wash fluid again into the sump 18. Then, the controller 38 drives the wash fluid spray device 10 and thus rinses the dishes with clean wash fluid. During the rinsing of the dishes, the controller 38 may drive the heating device 20 so as to heat the wash fluid used to rinse the dishes, and may supply rinsing agent into the washing tub 4 by driving the detergent supply device 14. The heating device 20 may heat the wash fluid in the sump 18 to a temperature of about 65° C. during the rinsing of the dishes.

Once the rinsing of the dishes is complete, the controller 38 terminates the operations of the heating device 20 and the spray device 10, and drains the sump 18 by driving the drain device 26. Thereafter, the controller 38 supplies hot air into the washing tub 4 by driving the drying device 42. As a result, the dishes in the washing tub 4 are dried by the hot air.

Once the drying of the dishes is complete, the controller 38 terminates the operation of the drying device 42, and thus, the operation of the dishwasher 1 is complete.

If the dishwasher 1 is driven repeatedly over a long period of time, dirt and waste wash fluid may accumulate in the washing tub 4, the sump 18, the spray device 10 and the heating device 20, and the accumulated dirt and waste fluid may be decomposed. Thus, an offensive odor may be emitted from the washing tub 4. In order to address this, the heating device 20 may heat wash fluid when no dishes are loaded in the washing tub 4, and the wash fluid spray device 10 may spray the heated wash fluid into the washing tub 4 and may thus sterilize and wash the washing tub 4. In order to sterilize and wash the washing tub 4, a switch provided in the manipulation device 16 exclusively for choosing a sterilization washing operation or at least one of the switches 16 a and 16 b may be manipulated.

Referring to FIG. 4, wash fluid remaining in the washing tub 4 is discharged (S1). Thereafter, clean wash fluid is supplied into the washing tub 4 (S2). Thereafter, the wash fluid supplied into the washing tub 4 is heated, and the washing tub 4 is sterilized and washed by spraying the heated wash fluid with the use of the wash fluid spray device 10 (S3 through S12). Thereafter, the wash fluid used to sterilize and wash the washing tub 4 is discharged (S13 and S14). Thereafter, the washing tub 4 is dried by supplying dry air into the washing tub 4 (S15). Thereafter, wash fluid remaining in the washing tub 4 is discharged (S16).

More specifically, the controller 38 discharges wash fluid remaining in the sump 18 by driving the drain device 26 for a predefined amount of time (S1). Thereafter, the controller 38 supplies clean wash fluid into the sump 18 by driving the supply device 24 for a predefined amount of time (S2). The operating times of the drain device 26 and the supply device 24 may be determined by the timer 40 and may then be provided to the controller 38. In the exemplary embodiment of FIG. 4, the drain device 26 may be driven for 43 seconds in operation S1, and the supply device 24 may be driven for 45 seconds in operation S2.

Thereafter, the controller 38 heats the wash fluid supplied into the sump 18 to a target temperature by driving the heating device 20, and the heating device 20 maintains the heated wash fluid at the target temperature (S3, S4, S5 and S9). Thereafter, the controller 38 sprays the heated wash fluid into the washing tub 4 by driving the wash fluid spray device 10 (S6, S7, S8, S10, S11 and S12). As a result, the washing tub 4 may be washed with clean wash fluid, and thus, wash fluid and dirt remaining in the washing tub 4, the sump 18, the wash fluid spray device 10, and the heating device 20 may be removed. In addition, since the washing tub 4 is sterilized with hot wash fluid, germs or mold can be prevented from breeding in the washing tub 4, the sump 18, the wash fluid spray device 10 and the heating device 20. The operating times of the heating device 20 and the wash fluid spray device 10 may be determined by the timer 40 and may then be provided to the controller 38.

The sterilization and washing of the washing tub 4 (S6, S7, S8, S10, S11, and S12) may continue for a first set time. However, if the amount of time elapsed after the heating of the wash fluid in the sump 18 exceeds a third set time (S9), the washing tub 4 may be preliminarily washed regardless of whether or not the wash fluid in the sump 18 has reached the target temperature. Therefore, it is possible to secure the performance of the washing of the washing tub 4 even when the heating of the wash fluid in the sump 18 takes longer than expected. In the exemplary embodiment of FIG. 4, the target temperature may be set to 80° C., and the first set time may be set to 20 minutes.

If the time taken to spray wash fluid into the washing tub 4 after the heating of the wash fluid in the sump 18 exceeds a second set time (S11) (after the first set time has elapsed), the controller 38 may supply a rinsing or sterilizing agent into the washing tub by driving the detergent supply device 14 (S12). The second set time may be shorter than the first set time. The second set time may be set to 15 minutes.

After the sterilization and washing or the washing tub 4 (S3 through S12), the controller 38 terminates the operations of the heating device 20 and the spray device 10 (S13), and discharges the wash fluid in the sump 18 by driving the drain device 26 for a predefined amount of time (S14). Thereafter, the controller 38 supplies hot dry air into the washing tub 4 by driving the drying device 42 for a predefined amount of time. As a result, the washing tub 4, the sump 18, the wash fluid spray device 10 and the heating device 20 are dried by hot air. During operation S16, the controller 38 completely drains the sump 18 by driving the drain device 26 for a predefined amount of time. In the exemplary embodiment of FIG. 4, the drain device 26 may be driven for 43 seconds in operations S13 and S14, the drying device 42 may be driven for 20 minutes, and the drain device may be 26 may be driven for 18 seconds in operation S16.

FIG. 5 is a block diagram of a dishwasher 10 according to another embodiment as broadly described herein. In FIGS. 1 through 5, like reference numerals indicate like elements, and thus, detailed descriptions thereof will be omitted. The exemplary embodiment of FIG. 5 will hereinafter be described in detail, mainly focusing on differences with the exemplary embodiment of FIGS. 1 through 4.

Referring to FIG. 5, the dishwasher includes a wash fluid spray device 110, which washes dishes loaded in a washing tub (not shown) by spraying wash fluid into the washing tub, a heating device 120, which heats wash fluid, and a controller 138, which controls the wash fluid spray device 110 and the heating device 120. The dishwasher 10 may also include a drying device 142, which dries the dishes by supplying dry air into the washing tub, a fluid supply device 124, which supplies wash fluid into the washing tub, and a manipulation device 116, which receives a manipulation signal for requesting a sterilization washing operation to be performed on the washing tub from a user. The dishwasher may also include a display 150, which displays various operating information regarding the sterilization and washing of the washing tub when the wash fluid spray device 110 and the heating device 120 are being driven, and a steam supply device 160, which supplies steam into the washing tub. A sheath heater having excellent watertight properties may be used as the heating device 120.

The operation of the dishwasher will hereinafter be described in detail. The user applies a manipulation signal to the dishwasher by manipulating the manipulation device 116. The dishwasher is driven and thus performs the method shown in FIG. 4 in response to the manipulation signal. More specifically, the controller 138 controls the heating device 120 to heat wash fluid when no dishes are loaded in the washing tub. Thereafter, the controller 138 controls the wash fluid spray device 110 to spray the heated wash fluid into the washing tub and thus to sterilize and wash the washing tub. Once the sterilization and washing of the washing tub is complete, the controller 138 controls the drying device 142 to supply dry air into the washing tub and thus to dry the washing tub.

If no dishes have been loaded in the washing tub for more than a predefined amount of time, the controller 138 may control the wash fluid spray device 110 to spray heated wash fluid into the washing tub and thus to sterilize and wash the washing tub regardless of whether a manipulation signal has been received from the user. Therefore, even if the user forgets sometimes to sterilize and wash the washing tub, it is possible for the dishwasher to automatically sterilize and wash the washing tub and thus to keep the washing tub clean.

The dishwasher may also include the manipulation device 116, which receives a manipulation signal for requesting the washing tub to be sterilized and washed from the user. The controller 138 may control the washing tub to be sterilized and washed by driving the wash fluid spray device 110 and the heating device 120 upon receiving the manipulation signal from the manipulation device 116. The manipulation device 116 may provide various sterilization washing courses, which may be performed in the same manner as or a similar manner to that described above. When the wash fluid spray device 110 and the heating device 120 are driven, the display 150 displays various operating information regarding the sterilization and washing of the washing tub to the user. Examples of the operating information displayed by the display 150 include information indicating when the sterilization and washing of the washing tub will be complete and information indicating the degree to which the washing tub is sterilized and washed.

The dishwasher may also include a residual fluid discharge device 170, which discharges fluid remaining in the washing tub. The residual fluid discharge device 170 may discharge fluid remaining in the washing tub before the supply of wash fluid into the washing tub by the fluid supply device 124 and after the drying of the washing tub by the drying device 142. Thus, it is possible to prevent an offensive odor and germs from being generated due to wash fluid remaining in the washing tub for a long time and thus to keep the washing tub clean.

The dishwasher may also include the steam supply device 160, which supplies steam into the washing tub. The steam supply device 160 may sterilize the washing tub with steam before the sterilization of the washing tub with heated wash fluid by the wash fluid spray device 110. Therefore, it is possible to remove germs that may exist in the washing tub. In addition, it is possible to preheat the washing tub and thus to effectively remove impurities adhered onto the washing tub with heated wash fluid.

In a dishwasher and a method as broadly described herein, it is possible to prevent a dishwasher from emitting an offensive odor due to wash fluid and impurities remaining in a washing tub and thus to improve the performance of a dishwasher.

Any reference in this specification to “one embodiment,” “an embodiment,” “example embodiment,” “certain embodiment,” “alternative embodiment,” etc., means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment as broadly described herein. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with any embodiment, it is submitted that it is within the purview of one skilled in the art to effect such feature, structure, or characteristic in connection with other ones of the embodiments.

Although embodiments have been described with reference to a number of illustrative embodiments thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles of this disclosure. More particularly, numerous variations and modifications are possible in the component parts and/or arrangements of the subject combination arrangement within the scope of the disclosure, the drawings and the appended claims. In addition to variations and modifications in the component parts and/or arrangements, alternative uses will also be apparent to those skilled in the art. 

1. A method of controlling a dishwasher, the method comprising: removing wash items from at least one rack positioned in a tub of the dishwasher such that the tub is empty of items to be washed; heating wash fluid stored in a sump positioned below the tub; and sterilizing the tub by spraying the heated wash fluid through a spray device into the empty tub.
 2. The method of claim 1, further comprising discharging the heated wash fluid used to sterilize the tub after sterilizing the tub.
 3. The method of claim 2, further comprising supplying dry, heated air into the tub after discharging the heated wash water to dry the tub.
 4. The method of claim 1, wherein sterilizing the tub comprises: heating the wash fluid to a target temperature; and operating the spray device for a first set time after the wash fluid reaches the target temperature, and maintaining the wash fluid in the tub at the target temperature while operating the spraying device.
 5. The method of claim 4, wherein sterilizing the tub further comprises, after the first set time has elapsed, supplying a rinsing and sterilizing agent into the tub and continuing to operate the spray device for a second set time.
 6. The method of claim 5, wherein the second set time is less than the first set time.
 7. The method of claim 5, wherein heating the wash fluid to a target temperature comprises heating the wash fluid to a temperature of approximately 80° C., and wherein operating the spray device for a first set time comprises operating the spray device for approximately 20 minutes after the washing fluid reaches approximately 80° C.
 8. The method of claim 7, wherein continuing to operate the spray device for a second set time comprises continuing to operate the spray device for approximately 15 minutes after the first set time of approximately 20 minutes has elapsed and the rinsing and sterilizing agent has been supplied to the tub.
 9. The method of claim 4, further comprising operating the spray device if a third set time has elapsed even if the wash fluid has not yet reached the target temperature.
 10. The method of claim 1, wherein sterilizing the tub comprises: receiving a request that the tub be sterilized through a manipulation device provided with the dishwasher; transmitting the request to the controller; supplying wash fluid to the tub and heating the wash fluid to a target temperature; operating the spray device for a first set time after the wash fluid reaches the target temperature, and maintaining the wash fluid in the tub at the target temperature while operating the spraying device; after the first set time has elapsed, supplying a rinsing and sterilizing agent to the tub and operating the spraying device for a second set time; discharging wash fluid from the tub, and operating a heating device for a predetermined time to dry the tub.
 11. The method of claim 1, wherein heating wash fluid and sterilizing the tub comprises: operating a timer and measuring an amount of time that has elapsed after removing wash items from the at least one rack; and if the elapsed time exceeds a predetermined amount of time, automatically initiating a sterilizing cycle, including: supplying wash fluid to the tub and heating the wash fluid to a target temperature; operating the spray device for a first set time after the wash fluid reaches the target temperature, and maintaining the wash fluid in the tub at the target temperature while operating the spraying device; after the first set time has elapsed, supplying a rinsing and sterilizing agent to the tub and operating the spraying device for a second set time; and discharging wash fluid from the tub, and operating a heating device for a predetermined time to dry the tub.
 12. A dishwasher, comprising: a tub having at least one rack positioned therein that receives items for washing; a spray device that sprays wash fluid into the tub so as to wash items received in the at least on rack; a heating device that heats wash fluid supplied to the tub through the spray device; and a controller that controls the heating device and the spray device so as to spray heated was fluid into the tub to wash and sterilize the tub when no items are received in the at least one rack.
 13. The dishwasher of claim 12, further comprising: a fluid supply device that supplies wash fluid to the tub; a drying device that supplies dry air to the tub so as to dry the tub, wherein the controller operates the drying device to dry the tub after the heating device and the spray device have washed and sterilized the tub; and a residual fluid discharge device that discharges fluid remaining in the tub before the fluid supply device supplies clean wash fluid to the tub, and after the heating device and the spray device have washed and sterilized the tub.
 14. The dishwasher of claim 13, further comprising: a manipulation device that receives input of requests for washing and sterilizing the tub and transmits a corresponding signal to the controller, wherein the controller controls the fluid supply device, the heating device, the spraying device, and the drying device based on the signal received from the manipulation device; and a display that displays an operation state of the dishwasher and information regarding the washing and sterilizing of the tub.
 15. The dishwasher of claim 13, further comprising a steam supply device that supplies steam to the tub so as to sterilize the tub with steam prior to spraying heated wash fluid into the tub through the spray device. 